// Status=review
.Receiver Noise Level

- Click the *Monitor* button to return to normal receive operation
(button should be highlighted in [green]*GREEN*).

- Set your transceiver to USB (or USB Data) mode.  

- Use the receiver gain controls and/or Windows mixer controls to set
the background noise level (scale at lower left of main window) to
around 30 dB with no signals present.  If necessary you can also use
the slider next to the scale, but note that the overall dynamic range
will be best with this slider not too far from its mid-point.

.Bandwidth and Frequency Setting

Taking full advantage of the wide-band, dual-mode capability of
_WSJT-X_ requires a receiver bandwidth of at least 4 kHz.  Many SSB
transceivers have a fixed-width Tx filter that will not pass audio
frequencies higher than about 2700 Hz.  _WSJT-X_ takes care of this by
using Split mode, receiving with *VFO A* and transmitting with *VFO
B*.  Under CAT control _WSJT-X_ offsets the Tx dial frequency (*VFO
B*) in 500 Hz steps, adjusting the generated audio frequency so that
it always falls in the range 1500 – 2000 Hz. With *CAT* and *Split Tx*
enabled on the configuration screen and your transceiver set to *Tx
Split* mode, this frequency control will be handled automatically.

If your transceiver has only a standard SSB filter you won’t be able
to use more than about 2.7 kHz bandwidth.  You can still have all of
the JT9 sub-band and part of the JT65 sub-band available on screen,
however.  On 20m, say, set dial frequency (*VFO A*) to 14.0774 and the
*JT9 nnnn JT65* dividing line at 1600 Hz.  JT9 signals in their
conventional sub-band will then appear at 1600 – 2600 Hz, while JT65
signals will be below 1000 Hz.  Of course, you might prefer to
concentrate on one mode at a time, setting your dial frequency to
(say) 14.076 for JT65 and 14.078 for JT9.  Present conventions have
the nominal JT9 dial frequency 2 kHz higher than the JT65 dial
frequency, and the checkbox labeled *+2 kHz*, just below the *Band*
selector, makes the appropriate settings easy.